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1.
大尺度下褐飞虱种群空间结构初步分析   总被引:3,自引:0,他引:3  
褐飞虱是我国主要的水稻害虫,有着复杂的空间结构.地统计学可用来分析空间相关变量的结构和插值模拟空间相关变量的分布.运用地统计学中的变差函数和克立格插值法对广东省褐飞虱种群3个主要世代在早稻田间的空间结构进行分析和模拟的结果表明,大尺度的褐飞虱田间种群的空间分布为聚集型,不同世代褐飞虱种群的局部空间结构有差异,聚集的范围分别为400、200和205km;空间分布模拟地图能反映褐飞虱种群在田间的具体分布情况,广东西部地区每一世代褐飞虱的发生密度均高于东部地区.  相似文献   

2.
采用Taylor幂法扩散法和Iwao回归法分析了云南元阳哈尼梯田1400~2000m海拔16个哈尼族传统水稻品种田白背飞虱Sogatella furcifera(Horvath)1~3龄若虫的空间分布特征。结果表明,白背飞虱1~3龄若虫在不同海拔、不同水稻品种田均呈聚集分布中的负二项分布,其负二项分布的公共K值为3.53,聚集原因主要是由白背飞虱生物学特性和环境因素引起。Iwao直线回归方程拟合公式为m*=3.96+1.09m(R=0.97),Taylor幂拟合公式为lg(V)=0.28+1.34×lg(m)(R=0.85)。其中,在1400~1500、1501~1600、1601~1700、1701~1800、1801~1900和1901~2000m海拔梯田稻田中,白背飞虱若虫平均拥挤度分别为10.74±0.83、23.67±3.50、21.64±6.02、47.10±5.71、52.59±12.75、13.72±3.14,差异显著(F=5.77,P<0.01),其中在1701~1800和1801~1900m海拔稻田中白背飞虱平均拥挤度最高,表明在该海拔处白背飞虱在稻丛上分布较为集中,而在1400~1500和1901~2000m海拔稻田中平均拥挤度最低。根据空间分布型参数,建立了精度分别为0.1和0.2时的理论抽样数模型,分别为n=1905.43x+34.57,n=476x.36+8.64,该模型适用于不同虫口密度下的田间抽样。当白背飞虱虫口密度为5、10、20头/丛时,分别取样30、20和15个样方。  相似文献   

3.
大尺度下褐飞属种群空间结构初步分析   总被引:15,自引:3,他引:12  
褐飞虱是我国主要的水稻害虫,有着复杂的空间结构,地统计学可用来分析空间相关变量的结构和插植模拟空间相关变量的分布,运用地统计学中的变差函数和克立格插值法对广东省褐飞虱种群3个主要世代在早稻田间的空间结构进行分析和模拟的结果表明,大尺度的褐飞虱田间种群的空间分布为聚集型,不同世代群在田间的具体分布情况,广东西部地区第一世代褐飞虱的发生密度均高于东部地区。  相似文献   

4.
基于GIS的瓜蚜种群空间结构和分布模拟   总被引:1,自引:0,他引:1  
运用地理信息系统(GIS)和地统计学分析方法,对2008年宁夏环香山地区压砂西甜瓜瓜蚜种群空间结构进行分析,并基于不同模型的普通Kriging插值法模拟了瓜蚜种群空间分布格局.结果表明:研究区瓜蚜数量在不同发生时期(初发期、盛发期和盛末期)均显示出明显不同的空间结构,其半变异函数均为指数型或高斯型,田间种群空间格局均呈聚集分布,不同时期的聚集程度(1-变异程度)均大于45%,空间相关范围在10.37~29.11 km,空间变异主要受空间自相关影响;空间分布模拟较好地从时间、空间两个角度直观地模拟不同时期瓜蚜种群的动态变化,易于确定瓜蚜的发生范围和发生程度.  相似文献   

5.
烟蚜及其捕食性天敌草间小黑蛛种群空间结构分析   总被引:1,自引:0,他引:1  
采用地统计学原理和方法,拟合了不同时期烟蚜种群及其捕食性天敌草间小黑蛛种群的空间结构模型,分析了其空间关系.结果表明,不同时期烟蚜种群的空间结构模型均为球型,空间格局呈聚集型分布,空间相关距离在2.0252~4.1495m之间,异质系数为10281.36~300216.30,空间依赖程度为12176.81~303433.70;不同时期草间小黑蛛种群的空间结构模型也均为球型,空间格局呈聚集型分布,空间相关距离在3.7328~4.8983m之间,异质系数为1.4482~4.4134,空间依赖程度为1.6941~5.8167.该结果和方法可用于监测烟田目标害虫的时空格局动态.  相似文献   

6.
根据2003-2009年重庆市秀山县白背飞虱迁入前期的田间调查资料,应用地理信息系统(GIS)结合传统空间分布分析方法,研究了该县白背飞虱空间分布格局及其动态.结果表明:2003-2009年的白背飞虱种群在全县范围呈现明显的聚集分布格局;反向距离插值图显示,不同年度聚集中心和聚集程度是变化的.总的分布格局是,秀山县中部平坝地区的官桥、官庄、平凯镇发生较重,7年的调查数据中有4年的聚集中心位于此;而周边三沟两岔地区发生相对较轻,只有2007年聚集中心位于南部,2008年的聚集中心位于东部,2009年聚集中心位于北部和西部.  相似文献   

7.
【目的】掌握云南稻区白背飞虱Sogatella furcifera,越冬虫源特征及其与田间种群大发生的相关性。【方法】2010-2015年,对云南省主要稻区白背飞虱的越冬虫情进行田间调查;2013年南京农业大学与云南省农科院的科研人员行程6 000 km联合对滇西、滇西南、滇南和滇东南等10县20个稻区进行了实地越冬调研。【结果】云南省各稻区白背飞虱越冬种群主要集中在23?57?N以南,海拔高度为1 608 m以下的稻区。同一稻区白背飞虱越冬虫口密度波动较大,一般在1 200头/667 m2之内,以若虫和成虫越冬,且若虫占总越冬虫量的97.33%,主要聚集在有水源的再生稻、稻桩、落粒苗和早稻秧苗上。本地越冬种群密度(越冬虫量)与秧田虫量、移栽期虫量、孕穗期虫量、大田总虫量的相关性并不显著(P0.05)。【结论】云南稻区本地越冬虫源数量对白背飞虱种群大发生的形成贡献十分有限。  相似文献   

8.
张蓉  冷允法  朱猛蒙  王芳 《应用生态学报》2007,18(11):2580-2585
运用地理信息系统(GIS)和地统计学方法对宁夏南部固原市原州区不同时期苜蓿斑蚜(Therioaphis trifolii)种群的空间结构进行了分析,并采用普通克立格插值法模拟了苜蓿斑蚜种群空间分布.结果表明:不同时期苜蓿斑蚜种群存在空间相关性,其半变异函数曲线均为指数型,空间格局呈聚集分布,空间变异成分的变化范围为34.13%~48.77%,空间相关范围为8.751~12.049km,聚集程度和方向有从西南向东北方向聚集的趋势.空间分布模拟图能较好地从时间、空间两个角度直观地分析不同时期苜蓿斑蚜种群的动态变化,易于确定同一时期苜蓿斑蚜的发生位置和发生程度.  相似文献   

9.
朝鲜球坚蚧及黑缘红瓢虫空间格局的地统计学研究   总被引:21,自引:3,他引:18  
利用地统计学方法研究了不同时期朝鲜球坚蚧(Didesmococcus Koreanus Borchs)若虫及黑缘红瓢虫(Chilocorus rulidus Hope)幼虫种群的空间分布格局和空间相关性。结果表明,不同时期朝鲜球坚蚧若虫种九和黑缘红瓢虫幼虫种群的半变异函数均可拟合为球型,其空间格局为聚集型,在小尺度上,空间变异主要是由其空间自相关引起的,且不同时期格局变化不明显,变程分别为9.56-15.70m和18.83-19.74m之间。黑缘红瓢虫种群与朝鲜球坚蚧种群之间具有很强的追随关系,说明黑缘红瓢虫种群是朝鲜球坚蚧种群的优势天敌。  相似文献   

10.
黑刺粉虱Aleurocanthus spiuiferus是茶园重要害虫之一,为明确黑刺粉虱在北方茶园的越冬分布型及越冬虫态,通过对茶园黑刺粉虱越冬代虫源进行调查,分冠层统计不同越冬时期各虫态的发生量,利用聚集度指标分析、m*-m回归方程分析和Taylor幂法则回归方程分析其空间分布型。结果显示黑刺粉虱越冬代田间分布型为聚集分布,种群聚集均数λ>2,聚集原因为种群自身产卵习性与环境因素共同作用结果;各虫态在茶树冠层间的分布存在差异,卵和1龄若虫主要分布于树冠中、上部,3龄、4龄若虫和伪蛹主要分布于树冠中、下部;随着越冬时间推移,卵和低龄若虫占比逐渐减少,至越冬结束黑刺粉虱4龄若虫和伪蛹占种群总量的80%。本研究明确了黑刺粉虱在北方茶园以各龄若虫和伪蛹越冬,越冬期间可缓慢发育至4龄若虫和伪蛹,越冬代田间分布型为聚集分布,研究结果可为黑刺粉虱精准预测预报和合理制定综合防治措施提供技术支持。  相似文献   

11.
12.
The present paper is part of taxonomic study on Chinese Phyllanthoideae. Included in it are two new varieties, Leptopus esquirolii var. villosus and Drypetes hainanensis var. longistipitata, one new combination, Glochidion triandrum var. siamense, and seven new records in China: Drypetes salicifolia, D. hoaensis. Actephila subsessilis, Glochidion khasicum, G. nubigennum, Bridelia spiosa and B. poilanei. In addition, seventeen taxon names are newly reduced: Liodendron formosanum = Drypetes formosana, Liodendron matsumurae = Drypetes matsumurae, D. longipes = D. indica, Antidesma paxii = A. acidum, A. hiiranense, A. filipes and A. pentandrum var. hiiranense = A. japonicum, A. calvescens = A. montanum, A. microphyllum = A. venosum, Breynia stipitata var. formosana and B. jormosana = B. vitis-idaea, Glochidion zeylanicum var. tomentosum = G. hirsutum, G. rubidulum = G. thomsonii, G. acuminatum = G. triandrum, G. fagifolium and Phyllanthus fagifolius = Glochidion sphaerogynum, Bridelia penangiena = B. insulana, B. henryana = B. tomentosa. All the types are kept in SCBl and PE.  相似文献   

13.
At one spectrum extreme, Astrobiology conjectures that for exoplanets with Goldilocks conditions, terrestrial-like life is inevitable. Moreover, it is envisaged that via panspermia, terrestrial-like life and its precursors are transferred among galaxies, stars, and within solar systems via transiting comets, asteroids, and planetoids. In addition, expelled stars, which have solar systems, it is inferred, transfer life as well. However, at the other extreme, we propose a paradigm shift that on some planets, subject to non- Goldilocks conditions, metal machine life could arise, ab initio, and evolve viruses, intelligence, and civilizations, conjointly. Accordingly, intelligent mechanized civilizations could readily and efficiently commence space exploration. Furthermore, as a counter paradigm shift, such civilizations could experiment and produce non-metallic life, based on carbon and other non-metal elements, under suitable conditions, related to Goldilocks life. Even a single example of validated interstellar or intergalactic communication received on the Earth would support the existence of life elsewhere. However, the communication platform should not be restricted to electromagnetic radiation. Other platforms should be included as well - one such example, which would require sophisticated technology, is neutrino communication. This is the case for any advanced civilization, be it metal-machine based, biological-based, and carbon-based. In sum, civilizations based on machine life, would be highly productive due to the longevity and hardiness of machine life. However, significant caveats are raised in this brief report, because possibly dissimilar psychologies and intelligence may lead to conflicts between metal machine life and biological life, inter-paradigm conflict.  相似文献   

14.
The phylogeny of groups within Gobioidei is examined with molecular sequence data. Gobioidei is a speciose, morphologically diverse group of teleost fishes, most of which are small, benthic, and marine. Efforts to hypothesize relationships among the gobioid groups have been hampered by the prevalence of reductive evolution among goby species; such reduction can make identification of informative morphological characters particularly difficult. Gobies have been variously grouped into two to nine families, several with included subfamilies, but most existing taxonomies are not phylogenetic and few cladistic hypotheses of relationships among goby groups have been advanced. In this study, representatives of eight of the nine gobioid familes (Eleotridae, Odontobutidae, Xenisthmidae, Gobiidae, Kraemeriidae, Schindleriidae, Microdesmidae, and Ptereleotridae), selected to sample broadly from the range of goby diversity, were examined. Complete sequence from the mitochondrial ND1, ND2, and COI genes (3573 bp) was used in a cladistic parsimony analysis to hypothesize relationships among the gobioid groups. A single most parsimonious topology was obtained, with decay indices indicating strong support for most nodes. Major phylogenetic conclusions include that Xenisthmidae is part of Eleotridae, and Eleotridae is paraphyletic with respect to a clade composed of Gobiidae, Microdesmidae, Ptereleotridae, Kraemeriidae, and Schindleriidae. Within this five-family clade, two clades are recovered. One includes Gobionellinae, which is paraphyletic with respect to Kraemeriidae, Sicydiinae, Oxudercinae, and Amblyopinae. The other contains Gobiinae, also paraphyletic, and including Microdesmidae, Ptereleotridae, and Schindleriidae. Previous morphological evidence for goby groupings is discussed; the phylogenetic hypothesis indicates that the morphological reduction observed in many goby species has been derived several times independently.  相似文献   

15.
1. Acetylcholine receptors were initially defined as nicotinic or muscarinic, based on selective activation by two natural products, nicotine and muscarine. Several further nicotinic agonists have been discovered from natural sources, including cytisine, anatoxin, ferruginine, anabaseine, epibatidine, and epiquinamide. These have provided lead structures for the design of a wide range of synthetic agents.2. Natural sources have also provided competitive nicotinic antagonists, such as the Erythrina alkaloids, the tubocurarines, and methyllycaconitine. Noncompetitive antagonists, such as the histrionicotoxins, various izidines, decahydroquinolines, spiropyrrolizidine oximes, pseudophrynamines, ibogaine, strychnine, cocaine, and sparteine have come from natural sources. Finally, galanthamine, codeine, and ivermectin represent positive modulators of nicotinic function, derived from natural sources.3. Clearly, research on acetylcholine receptors and functions has been dependent on key natural products and the synthetic agents that they inspired.  相似文献   

16.
The phylogenetic relationships of the caryophyllidia-bearing dorids are studied, based on the examination of the type species of all the genera previously described. The phylogenetic hypothesis supports that the caryophyllidia-bearing dorids are a monophyletic group and the sister group of the clade formed by Astemnotus Ehrenberg, 1831 and Halgerda Bergh, 1880. Several genera previously considered as valid or regarded as uncertain are here synonymized: Peronodoris Bergh, 1904, Trippa Bergh, 1877, Phlegmodoris Bergh, 1878, Petelodoris Bergh, 1881, Kentrodoris Bergh, 1876, Audura Bergh, 1878, Centrodoris P. Fischer, 1883, Anisodoris Bergh, 1898, Awuka Er. Marcus, 1955, Rhabdochiia P. Fischer, 1883, Boreodoris Odhner, 1939, Dictyodoris Bergh, 1880, Gravieria Vayssiere, 1912, Aporodoris Ihering, 1886. The following genera are regarded as valid: Astemnotus, Atagema J.E. Gray, 1850, Jorunna Bergh, 1876, Platydoris Bergh, 1877, Diaulula Bergh, 1878, Rostanga Bergh, 1879, Halgerda Bergh, 1880, Baptodoris Bergh, 1884, Gargamella Bergh, 1894, Alloiodoris Bergh, 1904, Sclerodoris Eliot, 1904, Taringa Er. Marcus, 1955, Thorybopus Bouchet, 1977. The new genus Nophodoris is described based on two new species from New Caledonia deep waters. Two additional new species from New Caledonia belonging to the genera Atagema and Gargamella are also described. Nomenclatural and taxonomic problems are discussed, and several type species, neotypes and lectotypes are selected.  相似文献   

17.
The species of the genus Trichoteleia Kieffer (Hymenoptera: Platygastridae) are revised: 42 species are recognized, of which two were previously named and are redescribed: Trichoteleia afo Talamas, sp. n., Trichoteleia albidipes Kieffer, Trichoteleia bicolor Talamas, sp. n.; Trichoteleia bidentata Talamas sp. n.; Trichoteleia carinata Talamas, sp. n.; Trichoteleia cincta Talamas & Masner, sp. n.; Trichoteleia delilah Talamas, sp. n.; Trichoteleia eburata Talamas, sp. n.; Trichoteleia echinata Talamas, sp. n.; Trichoteleia fisheri Talamas & Masner, sp. n.; Trichoteleia funesta Talamas, sp. n.; Trichoteleia halterata Talamas & Masner, sp. n.; Trichoteleia hemlyae Talamas & Masner, sp. n.; Trichoteleia irwini Talamas & Masner, sp. n.; Trichoteleia janus Talamas, sp. n.; Trichoteleia jiro Talamas, sp. n.; T. ketrona Talamas, sp. n.; Trichoteleia levii Talamas & Johnson, sp. n.; Trichoteleia longiventris Talamas & Masner, sp. n.; Trichoteleia minima Talamas, sp. n.; Trichoteleia nify Talamas & Masner, sp. n.; Trichoteleia oculea Talamas, sp. n.; Trichoteleia orona Talamas & Masner, sp. n.; Trichoteleia parvipennis Talamas & Masner, sp. n.; Trichoteleia pauliani (Risbec); Trichoteleia picturata Talamas, sp. n.; Trichoteleia prima Talamas, sp. n.; Trichoteleia prolixa Talamas, sp. n.; Trichoteleia quazii Talamas, sp. n.; Trichoteleia ravaka Talamas, sp. n.; Trichoteleia rugifrons Talamas & Masner, sp. n.; Trichoteleia solocis Talamas, sp. n.; Trichoteleia sphaerica Talamas, sp. n.; Trichoteleia subtilis Talamas & Masner, sp. n.; Trichoteleia tahotra Talamas & Masner, sp. n.; Trichoteleia takariva Talamas, sp. n.; Trichoteleia tezitra Talamas, sp. n.; Trichoteleia tigris Talamas, sp. n.; Trichoteleia tonsa Talamas, sp. n.; Trichoteleia warreni Talamas & Masner, sp. n.; Trichoteleia xantrox Talamas, sp. n.; Trichoteleia zuparkoi Talamas & Masner, sp. n. A neotype is designated for Trichoteleia albidipes and a lectotype is designated for Trichoteleia pauliani.  相似文献   

18.
This study describes a method for predicting and classifying oxygen-binding pro- teins. Firstly, support vector machine (SVM) modules were developed using amino acid composition and dipeptide composition for predicting oxygen-binding pro- teins, and achieved maximum accuracy of 85.5% and 87.8%, respectively. Sec- ondly, an SVM module was developed based on amino acid composition, classify- ing the predicted oxygen-binding proteins into six classes with accuracy of 95.8%, 97.5%, 97.5%, 96.9%, 99.4%, and 96.0% for erythrocruorin, hemerythrin, hemo- cyanin, hemoglobin, leghemoglobin, and myoglobin proteins, respectively. Finally, an SVM module was developed using dipeptide composition for classifying the oxygen-binding proteins, and achieved maximum accuracy of 96.1%, 98.7%, 98.7%, 85.6%, 99.6%, and 93.3% for the above six classes, respectively. All modules were trained and tested by five-fold cross validation. Based on the above approach, a web server Oxypred was developed for predicting and classifying oxygen-binding proteins(available from http://www.imtech.res.in/raghava/oxypred/).  相似文献   

19.
In this paper, one new species, four new varieties and thirteen new records of Characeae from Hunan, China, are reported. They are Chara quadriscutulum, sp. nov., Nitella axilliformis var. biformis, var. nov., N. microcarpa var. unicarpa, var. nov., Chara braunii var. cylindrospora, var. nov., C. hydropitys var. hunanensis, var. nov., Nitella microcarpa Braun, N. leptoclada Braun, N. annandalei Pal, N. confervacea A. Braun, N. gracilliformis J. Groves, N. inversa Imahori, N. musashiensis Morioka, N. paucicostata T. F. Allen, N. acuminata var. gollmeriana (A. Br.) Zanev. et Wood, Tolypella boldii Sawa. Chara longifolia Robinson, C. pistianensis J. Vilhelm, C. grovesii Pal.  相似文献   

20.
Mating systems are reported for taxa of polypores and agarics considered related. Taxa areDictyopanus pusillus, Favolus alveolaris, F. tenuiculus, Lentinus bertierii, L. crinitis, L. punctaticeps, L. strigellus, L. strigosus, L. suavissimus, Pleurotus australis, P. levis, P. tuberregium, Polyporus ciliatus, P. elegans, P. squamosus, andP. varius. All are tetrapolar exceptP. elegans.  相似文献   

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